This report describes the National Institute of Standards and Technology's role in the Integrated Vehicle-Based Safety Systems (IVBSS) program, a four-year safety initiative sponsored by the United States Department of Transportation (U.S. DOT) to develop and field test an integrated crash warning system to prevent rear-end, lane-change/merge and road departure crashes on light vehicles and heavy commercial trucks. NIST's primary role in the program included assisting in the development of verification test procedures, developing a measurement system, and providing field support for vehicle test activities. NIST used the measurement system to collect data for determining whether the prototype warning systems passed or failed all closed-course track tests and for characterizing warning system performance on public roads